Aflatoxin, a toxic metabolite of the mold Aspergillus flavus, has been described as one of the most potent hepatocarcinogens known. It has been isolated from staple foodstuffs as well as animal feeds in all parts of the world. Its toxicity to poultry and livestock is well documented and it has recently been implicated as a possible causative factor in human liver disease. Since elimination of aflatoxin from all foodstuffs is difficult we, and others, have been investigating the possibility that an additive or some dietary modification might be employed to increase tolerance or improve resistance to the toxin. In this proposal we wish to study the difference in lipid metabolism which occur in the animal during active detoxification of the aflatoxin as compared to animals that have been exposed to aflatoxin for a short period of time and then maintained on control diets to allow time for tumor development. We also wish to clarify the effect of graded levels of two different dietary fats (lard and corn oil) on aflatoxin toxicity and in addition we wish to study the effects of Vitamin E deficiency on aflatoxin toxicity in rats that are being fed the aforementioned diets.